How to show Custom Lookup and respective values on selection of Seeded category field value.

Hi Experts
We have below requirement :

We are using seeded category hierarchy field. Where we are showing L1 to L4 levels.
What we want when user selects the Category then Custom Lookup needs to populate on the page and having the values as Categories attributes.

Ex - As per screenshot if user selecting Work Visa as category then Custom Lookup (Select the Attribute) come on page and having values as Work Visa attributes(highlighted in green).

Thanks
Ritesh